Tire Pressure Monitoring Systems (TPMS) have been used on luxury vehicles since the 1980's and implemented in light motor vehicles since Sep. 1 2007 in accordance with the Transport Recall Enhancement, Accountability and Documentation Act (TREAD Act). TPMS allows monitoring information related to a vehicle tire, such as tire air pressure. The TPMS transmits this monitoring information to the vehicle's onboard computer. For instance, when the air pressure in one or more of the tires is not sufficient, the onboard computer triggers an alert to inform the vehicle driver. Direct type systems use a wireless sensor in each of the four tire air chambers to communicate temperature and pressure related information to the vehicle's onboard computer. Presented in FIG. 1A is a vehicle 100 having a conventional direct type TPMS. The TPMS has an onboard computer 102 adapted to receive tire parameter information from sensors 104 positioned within each tire of the vehicle 100. The onboard computer 102 is adapted to send a general tire status information to a driver communication interface, such as a dashboard, according to the received tire parameter information. If the information received by the onboard computer 102 is not within the threshold set by the manufacturer, the onboard computer 102 sends an alert trigger to the dashboard, in order to inform the driver of a tire problem. In some cases, the alert trigger will disable the entire dashboard from its other functions as well as other display information.
Although the use of TPMS may be beneficial in detecting tire pressure or temperature issues, in many instances drivers experience false warnings that are unnecessarily expensive to repair in addition to being distracting and annoying for the driver. For instance, in the event where one of the four sensors 104 malfunctions, such as indicated by malfunctioning sensor 106 of FIG. 1B, the driver is alerted just as though the tire pressure were inadequate. The onboard computer 102 will also raise an alert if one or more sensors are removed from the vehicle. This situation is often encountered with the installation of winter tires, off-road tires, race tires or simply for vehicles having multiple sets of tires, since TPMS units are often physically damaged with the removal and installation of tires on the vehicle wheels. Moreover, Original Equipment Manufacturer (OEM) TPMS units are placed inside each vehicle's tire and are not easily accessible or replaceable in case of a fault. The sensors 104 are battery powered and have a certain lifespan after which their signal strength depletes and eventually causes them to stop functioning. It has also been noticed that steel belted radial tires block signal transmission paths and prevent transmission of information from the wireless sensors to the onboard computer 102, thereby generating a false warning. TPMS warnings could indeed be generated for various reasons that are not always due to a faulty tire. Repairing a false TPMS warning often requires the skills of an automotive mechanic and unnecessarily increases the maintenance cost of the vehicle.
In order to ignore such warnings from the TPMS, some have developed a device that eliminates receiving a TPMS signal. The device sends a wired signal to the onboard computer 102 indicating that the tire pressures are within the prescribed threshold. However, TPMS signals from all four wireless sensors become undetectable and even true warnings from the TPMS sensor are ignored. Moreover, the existing device is vehicle specific, complicated to install and often requires special skills to install. For example, Macht Schnell™ TPMS/RDC overriding module 108, as presented in prior art FIG. 1C, is manufactured specifically for BMW vehicles and is limited to North American BMW vehicle models only. As presented in FIGS. 1D and 1E, the module 108 needs to be physically hardwired into the car's TPMS system by the tire pressure control (RDC) wiring harness 110 o function. The module 108 must be connected directly to the car's onboard computer 102 via the original tire pressure control wiring harness 110, overriding the OEM TPMS/RDC module entirely. When activated, such as by lifting up a driver's side window, the module communicates with the onboard computer 102 telling it that it has received the correct pressure readings from all four tires in order to ignore any signal from the sensor including “o.k.” signals, true warning signals and false warning signals. This system entirely disables the tire pressure monitoring system by generating a wired signal between the physical RDC module and the onboard computer 102.
There is a need for a device that allows to ignore a TPMS false warning coming only from a specific tire 106 and still allow TPMS sensors 104 that function correctly to communicate with the onboard computer 102. If the driver of the vehicle sees a warning signal with respect to one tire, the driver should have the choice to ignore that warning signal and still have the possibility to monitor the tire status of the other properly functioning tires. Moreover, there is a need for a device that is easier to install without requiring the help of a mechanic with special skills.